In their recent paper published in Energy and Environmental Science (DOI: 10.1039/D0EE00825G), Zhang et al. demonstrated that if a part of the Au/n-Si Schottky junction is kept in shadow and the remaining under illumination, a potential difference is generated between the illuminated and the shadowed part. The authors explained the effect by invoking modulation of the work function of the Au electrode under illumination contrast. In this comment, we provide an alternative physical mechanism for the observed effect by considering the Schottky junction under illumination contrast to consist of two parallel Schottky junction solar cells, one at the shadowed and the other at the illuminated part, connected with each other in a closed loop circuit through the Si substrate and the top electrode. To test the proposed mechanism, we have fabricated ITO/n-Si and Au/n-Si Schottky junction devices. The values of open circuit voltage in the devices under illumination contrast are found to be matching with the difference of photovoltages of the two cells corrected for the potential drop across the Si substrate, which validates the proposed mechanism. To further corroborate the mechanism, the resistance of the Si substrate is short-circuited using ohmic contacts, which results in higher open circuit voltage and short circuit current from the device under illumination contrast. Although energy can be harvested from illumination contrast in a Schottky junction following the methods of Zhang et al., the presence of a closed loop in the equivalent circuit of the devices would lead to wastage of harvested energy.

中文翻译：

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Q. Zhang。Q. Liang。DK Nandakumar，SK Ravi，H. Qu，L.Suresh，X. Zhang，Y.Zhang，L.Yang，ATS Wee和SC Tan评论“从阴影效应中获取能量” ，能源环境。科学，2020，13，2404

Zhang等人在最近发表在《能源与环境科学》（DOI：10.1039 / D0EE00825G）上的论文中。证明如果Au / n的一部分-Si肖特基结保持在阴影中，其余保持在照明下，在被照明的部分和被阴影的部分之间会产生电势差。作者通过在照明对比度下调用Au电极功函数的调制来解释这种效果。在此评论中，我们通过考虑在光照对比下的肖特基结由两个平行的肖特基结太阳能电池组成，其中一个在阴影部分，另一个在照明部分，彼此连接在一起，从而为观察到的效果提供了一种替代的物理机制。通过硅衬底和顶部电极的闭环电路。为了测试提出的机制，我们制造了ITO / n -Si和Au / n-Si肖特基结器件。发现在照明对比度下的器件中的开路电压值与针对硅衬底上的电势降校正的两个单元的光电压差相匹配，这验证了所提出的机制。为了进一步证实该机制，使用欧姆接触使Si衬底的电阻短路，这会导致更高的开路电压和在照明对比度下来自器件的短路电流。尽管可以按照张等人的方法从肖特基结中的照明对比度中收集能量。，在设备的等效电路中存在闭环会导致浪费所收集的能量。